docs: def register(self, condition_set):
          """
          Registers a condition set with the manager.
  
          >>> condition_set = MyConditionSet() #doctest: +SKIP
          >>> gargoyle.register(condition_set) #doctest: +SKIP
          """
  
          if callable(condition_set):
              condition_set = condition_set()
          self._registry[condition_set.get_id()] = condition_set